De-contented fluid ejection

ABSTRACT

In example implementations, a system is provided. The system includes at least one fluid ejection apparatus, a heater and an energy source. The at least one fluid ejection apparatus dispenses a de-contented fluid onto a substrate during conveyance of the substrate. The heater is arranged after the at least one fluid ejection apparatus along a substrate conveying path. The heater removes a liquid from the de-contented fluid on the substrate such that the particles of the de-contented fluid remain on the substrate. The energy source is arranged after the heater along the substrate conveying path. The energy source applies energy to the substrate during the conveyance of the substrate to heat the substrate to a temperature that is approximately a melting temperature of the substrate to fuse the particles on the substrate to the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/332,200, filed on Mar. 11, 2019, which is a 371(c) National PhaseApplication of International Application No. PCT/2016/056633, filed Oct.12, 2016, both of which are herein incorporated by reference in theirentireties.

BACKGROUND

De-contented ink is not commonly used to print on media such as paper.De-contented ink has desirable properties such as better jettability,longer shelf life, and low volatile organic compound (VOC) emissions.

Other types of media, such as plastics, use inks that contain non-polar,water insoluble and high molecular binders that are jetted together withpigment colorants. These types of inks contain large amount ofco-solvent to facilitate the jetting and to swell the plastic substrate.These co-solvents have to be driven away by heating. This is followed byfusing. This process can limit print speeds and create VOC issues.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example system of the presentdisclosure;

FIG. 2 is a more detailed block diagram of the example system of thepresent disclosure;

FIG. 3 is another more detailed block diagram of the example system ofthe present disclosure;

FIG. 4 is an example close up diagram of the particles being imbibed bya substrate;

FIG. 5 is an example chart of absorption percentages at differentwavelengths for different colors; and

FIG. 6 is a flow diagram of an example method for printing de-contentedink on a plastic substrate.

DETAILED DESCRIPTION

The present disclosure discloses a system and method for printing onplastic substrates. As discussed above, some methods used to print onplastic substrates do not print a durable image. The ink that is appliedto the plastic substrate can be easily removed.

Some solutions include using inks that contain non-polar, waterinsoluble, and high molecular weight latex binders that are jettedtogether with pigment colorants, as described above to achievedurability. However, these types of inks contain large amounts ofco-solvents to facilitate the jetting and to swell the plasticsubstrate. These co-solvents have to be driven away, then the ink filmis fused at high temperatures. However, this process can limit printspeeds and create VOC issues.

In addition, the non-polar, water insoluble, high molecular weight latexbinder can create an insoluble crust on the printing nozzle surface. Theinsoluble crust can gradually block the jetting nozzle. As a result,jetting may not be sustained and reliable jetting may not be achieved.

It would be preferable to use de-contented ink to print on plasticsubstrates. De-contented inks are inks that do not include any binder orsolvents. A de-contented inks has desirable properties such as a longershelf life, better jettability, and low VOC emissions. However,de-contented ink does not generate durable images on plastic substratesbecause there is no binder to bind the pigments on the plasticsubstrates.

The present disclosure provides a system that can produce a durableimage on a substrate (e.g., plastic-based substrates) using de-contentedink. A durable image may be defined as an image that can withstand aneraser rub, wiping with a liquid such as 70% isopropylalcohol (IPA) orWindex®, tape adhesion, and the like.

In one implementation, energizing the de-contented ink film, e.g.,heating the particles of de-contented ink to a temperature that is closeto, or just below, a melting temperature of the plastic substrate,produces a durable image. Heating the particles of de-contented inkallows the particles to diffuse or melt into the surfaces of the plasticsubstrate. In other words, the particles can be imbibed by the plasticsubstrate. Said another way, some hydrophobic binder may migrate intothe condensed pigment matrices, thereby, generating a durable image.

FIG. 1 illustrates a block diagram of an example system 100 of thepresent disclosure. The system 100 includes a fluid ejection system 102,a processor 104, a memory 106 and an input/output (I/O) interface 108.In one example, the fluid ejection system 102 may be used to print onsubstrates. For example, the fluid ejection system 102 may be a printer,a multi-function device, a distributed printing system, and the like.

In one implementation, the fluid ejection system 102 may include a fluidejection apparatus 110, a heater 112, and an energy source 114. Examplesand additional details of the fluid ejection apparatus 110, the heater112 and the energy source 114 are described below.

As will be appreciated, the fluid ejection system 102, as describedherein, may selectively eject droplets of fluid such that the dropletsof fluid may be deposited on a substrate. The patterning of suchdeposited droplets of fluid on the substrate may cause an image to beformed on the substrate. Such formation of an image may be referred toas printing.

In one example, the processor 104 may control operation of the fluidejection system 102 and the various components within the fluid ejectionsystem 102. In one example, the memory 106 may be a non-transitorycomputer readable medium that stores instructions that are executed bythe processor. In one example, the I/O interface 108 may include adisplay, a keyboard, an input device (e.g., a mouse or a touchpad), andthe like. The I/O interface 108 may allow a user to enter a print jobthat is executed by the fluid ejection system 102 under control of theprocessor 104.

It should be noted that the system 100 may include additional componentsnot shown. For example, the system 100 may also include a feedback loop,communication modules, and the like.

FIG. 2 illustrates a block diagram of an example fluid ejection system102. In one implementation, the fluid ejection system 102 may include atleast one fluid ejection apparatus 202, a heater 204 and an energysource 206. In one example, the energy source 206 may be a lightemitting diode (LED) based energy source that includes one LED or aplurality of LEDs. The heater 204 may be arranged along a substrateconveying path 218 after the fluid ejection apparatus 202. The energysource 206 may be arranged along the substrate conveying path 218 afterthe heater 204.

In one example, a substrate 208 may be moved along the substrateconveying path 218 below the fluid ejection apparatus 202, the heater204 and the energy source 206. In one example, the substrate 208 may bea plastic. For example, the plastic may be a poly vinyl chloride (PVC),polycarbonate, or any other plastic.

In another example, the fluid ejection apparatus 202, the heater 204 andthe energy source 206 may be moved over the substrate 208 (e.g., via amovable carriage). It should be noted that although the substrateconveying path 218 is illustrated as moving from left to right in FIG. 2that the substrate conveying path 218 may also move from right to leftif the order of the fluid ejection apparatus 202, the heater 204 and theenergy source 206 are rearranged.

In one example, the fluid ejection apparatus 202 may eject, or dispense,a de-contented fluid 210 onto the substrate 208. The de-contented fluid210 may be an ink that does not contain any binders, such aspolyurethane, grafted polyurethane (PUG), latexes or small amounts ofsolvent. In one example, the de-contented fluid 210 may be a water basedink that is easily jettable and has low VOC emissions.

Although a single fluid ejection apparatus 202 is illustrated in FIG. 2,it should be noted that the fluid ejection system 102 may include aplurality of fluid ejection apparatuses 202. For example, the fluidejection system 102 may be a distributed print system that uses aplurality of fluid ejection apparatuses 202 to print across a width ofthe substrate 208. In other words, the number of the plurality of fluidejection apparatuses 202 may correspond to a width of the substrate 208.

In one example, the single fluid ejection apparatus 202 may dispense aplurality of different colored de-contented fluids 210. In anotherexample, a plurality of fluid ejection apparatuses 202 may each dispensea different colored de-contented fluid 210 or each dispense a pluralityof different colored de-contented fluids 210.

In one example, the heater 204 may remove liquid 212 from thede-contented fluid 210 that is applied to the substrate 208. As aresult, particles 214 of the de-contented fluid 210 may remain on thesubstrate 208 after the de-contented fluid 210 is dried. In one example,the liquid 212 that is removed may be water.

As the substrate 208 moves along the substrate conveying path 218, theparticles 214 that remain on the substrate 208 may pass below the energysource 206. The energy source 206 may emit energy that is absorbed bythe particles 214. The particles 214 may be heated to a temperature thatis just below a melting temperature of the substrate 208.

Using an LED based energy source 206 may provide many advantages overother heating methods. In one example, the LED based energy source 206may be instantly turned on and off to precisely control the amount ofenergy that is applied, and thereby, the temperature of the particles214 when the LED based energy source 206 is activated. In contrast,other heating methods such as thermal fusion or infrared heating cancontinue to heat the atmosphere around the particles 214 even when theenergy source is turned off.

In addition, the LED based energy source 206 may be more selective. TheLED based energy source 206 may be directed towards specific areas ofthe substrate 208. In other words, the LED based energy source 206 mayprovide a more targeted heating.

Moreover, different LEDs of the LED based energy source 206 may applyenergy to different specific colors. For example, fluid ejection system102 may be a cyan, magenta, yellow, key (or black) (CYMK) color printer.Each color (e.g., cyan, magenta, yellow and black) may absorb differentwavelengths of light to be energized, or heated. FIG. 5 illustrates anexample chart 500 that illustrates the absorption percentages atdifferent wavelengths for different colors.

The chart 500 illustrates a wavelength of an example LED. The wavelengthemitted by the example LED in the chart 500 may be absorbed at highpercentages by the yellow and black colors of the example ink. A secondLED may be used to emit wavelengths around 520 nanometers (nm) to 580 nmto heat the cyan and magenta colors.

As a result, the LED based energy source 206 may have a plurality ofdifferent LED lights that each emit a different wavelength of energy. Inother words, each one of the plurality of different LED lights may be adifferent color that emits a different wavelength of light onto theparticles 214. Depending on the colors of the particles 214 on thesubstrate 208, different LED lights of the LED based energy source 206may be selectively turned on and off.

The particles 214 may be dried in one cycle under the LED based energysource 206. In another example, the particles 214 may be dried viamultiple cycles under the LED based energy source 206. For example, eachcycle may melt different colored particles 214 using different LEDenergy wavelengths of the LED based energy source 206.

In one example, the particles 214 may be heated quickly by the LED basedenergy source 206. For example, the particles 214 may be exposed to theLED based energy source 206 for only a few seconds. For example, thesubstrate conveying path 218 may be moved at a rate of approximatelyseven feet per minute.

Referring back to FIG. 2, after the particles 214 are melted, theparticles 214 may be infused into, or imbibed by, the substrate 208. Asnoted above, the particles 214 may be heated to a temperature that isapproximately a melting temperature of the substrate 208. In oneexample, the temperature may be just below the melting temperature ofthe substrate 208. In one example, the melting temperature of thesubstrate 208 may be approximately 150 degrees Celsius (° C.). Inanother example, where the substrate 208 is polypropylene orpolyethylene, the melting temperature may be lower than 150° C.

FIG. 4 illustrates an example close up diagram of the particles 404being imbibed by a plastic substrate 402. As noted above, previousattempts to print on plastic substrates using de-contented ink were notvery successful. For example, the de-contented ink could be removedeasily.

However, by heating the particles 404 up to a temperature that is justbelow the melting temperature of the plastic substrate 402, theparticles 404 may be melted. As the substrate 402 reaches near a meltingtemperature, imperfections may be created in a top surface 406 of theplastic substrate 402. The melted particles 404 may be diffused into, orimbibed by, the imperfections of the top surface 406 of the plasticsubstrate 402. As a result, the printed image may have better adhesionto the plastic substrate 402 than in previous methods, thereby, creatinga more durable printed image.

However, if the substrate 208 has a melting temperature that is greaterthan 150° C., then heating the particles 214 to a temperature that isjust below the melting temperature may negatively affect the particles214. As a result, a primer may be applied to the substrate 208 asillustrated in FIG. 3 for substrates 208 that have a melting temperaturethat is greater than a temperature at which the particles 214 may beginto decompose (e.g., greater than 200° C.).

The example fluid ejection system 102 in FIG. 3 may include a primerapplying device 302, at least one fluid ejection apparatus 304, a heater306 and an LED energy source 310. The at least one fluid ejectionapparatus 304 may be arranged along a substrate conveying path 314 afterthe primer applying device 302. The heater 306 may be arranged along thesubstrate conveying path 314 after the fluid ejection apparatus 304. TheLED energy source 310 may be arranged along the substrate conveying path314 after the heater 306.

In one example, a substrate 312 may be moved along the substrateconveying path 314 below the primer applying device 302, the fluidejection apparatus 304, the heater 306 and the LED energy source 310.

In another example, the primer applying device 302, the fluid ejectionapparatus 304, the heater 306 and the LED energy source 310 may be movedover the substrate 312 (e.g., via a movable carriage). It should benoted that although the substrate conveying path 314 is illustrated asmoving from left to right in FIG. 3, the substrate conveying path 314may also move from left to right if the order of the primer applyingdevice 302, the fluid ejection apparatus 304, the heater 306 and the LEDenergy source 310 are rearranged.

In one example, the substrate 312 may be a plastic substrate that has amelting temperature that is higher than 150° C. As a result, heating theparticles 320 that are left by de-contented fluid 318 that is dispensedby the fluid ejection apparatus 304 to temperatures higher than 150° C.may damage the particles 320. For example, the particles may becomedecomposed at temperatures around 200° C. and higher.

As a result, a primer 316 may be dispensed, or applied, onto thesubstrate 312 before the de-contented fluid 318 is dispensed. The primer316 may be a thermally fusible primer. The thermally fusible primer maybe a latex or a wax.

In another implementation, the primer layer may be coated with adifferent coating method. For example, the coating method may includeGravure coating, reverse roll coating, knife-over-roll coating, meteringrod coating, slot die coating, curtain coating, air knife coating, andthe like. The coating may be dried before reaching the fluid ejectionapparatus 304.

The fluid ejection apparatus 304 may then dispense the de-contentedfluid 318 onto the primer 316 to print an image. Although a single fluidejection apparatus 304 is illustrated in FIG. 3, it should be noted thatthe fluid ejection system 102 may include a plurality of fluid ejectionapparatuses 304. For example, the fluid ejection system 102 may be adistributed print system that uses a plurality of fluid ejectionapparatuses 304 to print across a width of the substrate 312. In otherwords, the number of the plurality of fluid ejection apparatuses 304 maycorrespond to a width of the substrate 312.

In one example, the single fluid ejection apparatus 304 may dispense aplurality of different colored de-contented fluids 318. In anotherexample, a plurality of fluid ejection apparatuses 304 may each dispensea different colored de-contented fluid 318 or each dispense a pluralityof different colored de-contented fluids 318.

In one example, the heater 306 may remove liquid 308 from thede-contented fluid 318 that is applied to the substrate 312. As aresult, the particles 320 of the de-contented fluid 318 may remain onthe substrate 312 after the de-contented fluid 318 is dried. In oneexample, the liquid 308 that is removed may be water.

As the substrate 312 moves along the substrate conveying path 314, theparticles 320 that remain on the substrate 312 may pass below the LEDenergy source 310. The LED energy source 310 may emit energy that isabsorbed by the particles 320. The particles 320 may be heated to atemperature that is just below a melting temperature of the primer 316.In one example, the temperature may be a temperature just below themelting temperature of the primer 316 (e.g., just below 150° C.).

After the particles are melted, the particles 214 may be infused intothe primer 316. The primer 316 may be adhered to the substrate 312. Theuse of the primer 316 allows the substrate 312 to be a variety ofdifferent materials. For example, in addition to plastics that have amelting temperature below 150° C., the substrate 312 may also beplastics that have a melting temperature above 150° C., metals, and thelike.

FIG. 6 illustrates a flow diagram of an example method 600 for printingde-contented ink on a plastic substrate. In one example, the blocks ofthe method 600 may be performed by the system 100 or the fluid ejectionsystem 102.

At block 602, the method 600 begins. At block 604, the method 600applies a de-contented fluid on a plastic substrate to print an image.For example, the de-contented fluid may be an ink having one or moredifferent colors that are applied by a fluid ejection apparatus to printthe image on the plastic substrate.

In some implementations, a primer may be applied to the plasticsubstrate before the de-contented fluid is dispensed onto the plasticsubstrate. The primer may be a thermally fusible primer.

At block 606, the method 600 dries the de-contented fluid to removewater from the de-contented fluid. In one example, a heater may applyheat to the de-contented fluid to remove liquid (e.g., water) from thede-contented fluid.

At block 608, the method 600 applies energy from at least one LED toheat the de-contented fluid that is dried to a temperature that is atapproximately a melting temperature of the plastic substrate. In oneimplementation, the LED may be part of an LED energy source. The LEDenergy source may have a plurality of different LEDs to emit energy atdifferent wavelengths. The different wavelengths may be selectivelyabsorbed by different colors of particles that remain on the plasticsubstrate after the liquid is removed from the de-contented fluid.

The energy emitted by the LED may be absorbed by the particles to heatthe particles and melt the particles. In one example, the meltingtemperature of the plastic substrate may be approximately 150° C. andthe particles may be heated to a temperature that is just below themelting temperature, or just below 150° C. At block 610, the method 600ends.

It will be appreciated that variants of the above-disclosed and otherfeatures and functions, or alternatives thereof, may be combined intomany other different systems or applications. Furthermore, the term“approximately” when used with regard to a value may correspond to arange of ±10%. Various presently unforeseen or unanticipatedalternatives, modifications, variations, or improvements therein may besubsequently made by those skilled in the art which are also intended tobe encompassed by the following claims.

1. A system, comprising: a fluid ejection apparatus to dispense ade-contented fluid onto a plastic substrate; a heater to remove a liquidfrom the de-contented fluid on the plastic substrate such that particlesof the de-contented fluid remain on the plastic substrate; an energysource to apply energy to the plastic substrate; and a processor tocontrol the fluid ejection apparatus to dispense the de-contented fluid,to control the heater to heat the de-contented fluid to remove theliquid from the de-contented fluid, and to control the energy source toapply the energy to the plastic substrate until the plastic substrate isheated to a temperature that is approximately a melting temperature ofthe plastic substrate to create imperfections on a top surface of theplastic substrate, wherein particles that are melted are fused to theplastic substrate via the imperfections.
 2. The system of claim 1,wherein the fluid ejection apparatus comprises a plurality of fluidejection apparatuses.
 3. The system of claim 2, wherein the plurality offluid ejection apparatuses corresponds to a width of the plasticsubstrate.
 4. The system of claim 2, wherein each one of the pluralityof fluid ejection apparatuses dispenses a different colored de-contentedfluid.
 5. The system of claim 1, wherein the energy source comprises aplurality of light emitting diodes (LEDs), wherein the plurality of LEDsemits energy at different wavelengths in accordance with an absorptionpercentage of a respective color of the de-contented fluid on theplastic substrate.
 6. The system of claim 5, wherein the processor is tocontrol the plurality of LEDs to turn on and off to control the amountof energy that is applied and to direct the plurality of LEDs towards aspecific area of the plastic substrate to provide targeted heating. 7.The system of claim 1, wherein the melting temperature of the plasticsubstrate is below 150 degrees Celsius.
 8. The system of claim 1, wherethe plastic substrate comprises poly vinyl chloride, polycarbonate,polypropylene, or polytehylene.
 9. The system of claim 1, wherein thede-contented fluid comprises a jettable ink that does not contain anybinders.
 10. A system, comprising: a primer applying apparatus to applya primer onto a plastic substrate; a fluid ejection apparatus todispense a de-contented fluid onto the primer that has been applied tothe plastic substrate; a heater to remove a liquid from the de-contentedfluid on the plastic substrate such that particles of the de-contentedfluid remain on the plastic substrate; an energy source to apply energyto the plastic substrate; and a processor to control the primer applyingapparatus to apply the primer onto the plastic substrate, to control thefluid ejection apparatus to dispense the de-contented fluid, to controlthe heater to heat the de-contented fluid to remove the liquid from thede-contented fluid, and to control the energy source to apply the energyto the plastic substrate until the plastic substrate is heated to atemperature that is approximately a melting temperature of the plasticsubstrate to create imperfections on a top surface of the plasticsubstrate, wherein particles that are melted are fused to the plasticsubstrate via the imperfections.
 11. The system of claim 10, wherein themelting temperature of the plastic substrate is greater than 150 degreesCelsius.
 12. The system of claim 11, wherein the primer comprises athermally fusible primer, wherein a melting temperature of the primer isless than 150 degrees Celsius.
 13. The system of claim 10, wherein thefluid ejection apparatus comprises a plurality of fluid ejectionapparatuses.
 14. The system of claim 13, wherein each one of theplurality of fluid ejection apparatuses dispenses a different coloredde-contented fluid.
 15. The system of claim 10, wherein the energysource comprises a plurality of light emitting diodes (LEDs), whereinthe plurality of LEDs emits energy at different wavelengths inaccordance with an absorption percentage of a respective color of thede-contented fluid on the plastic substrate.
 16. The system of claim 15,wherein the primer is dried on the plastic substrate before the plasticsubstrate is conveyed to the fluid ejection apparatus.
 17. A method,comprising: controlling, via a processor, a fluid ejection apparatus todispense a de-contented fluid onto a plastic substrate to print animage; controlling, via the processor, a heater to heat the de-contentedfluid to remove water from the de-contented fluid such that particles ofthe de-contented fluid remain on the plastic substrate; and controlling,via the processor, an energy source to apply energy from a plurality oflight emitting diodes (LEDs) to the plastic substrate to heat theplastic substrate to a temperature that is approximately a meltingtemperature of the plastic substrate to create imperfections on a topsurface of the plastic substrate, wherein particles that are melted arefused to the plastic substrate via the imperfections.
 18. The method ofclaim 17, wherein controlling the fluid ejection apparatus comprises:controlling, via the processor, the fluid ejection apparatus to eject aplurality of different colored de-contented fluids on the plasticsubstrate.
 19. The method of claim 18, wherein the plurality of LEDs iscontrolled such that each LED emits a different wavelength of energybased on an absorption percentage of a color of the plurality ofdifferent colored de-contented fluids on the plastic substrate.
 20. Themethod of claim 17, wherein the melting temperature is approximately 150degrees Celsius and the temperature is less than 150 degrees Celsius.